It is planned to study the mechanism and control of energy transducing processes in normal and tumor cells. Three ion pumps and several channels will be investigated. The proton translocating pump of mitochondria, the Ca 2 ion pump of sarcoplasmic reticulum, and the Na ion K ion pump of the plasma membrane are the ATP driven pumps that will be analyzed. Specific emphasis will be placed on the phosphorylation process of the beta subunit of the Na ion K ion ATPase which we have shown renders the pump inefficient in tumor cells. The studies on the proton pump of mitochondria will be continued with emphasis on the purification and characterization of the 28,000 dalton subunit of the hydrophobic sector. Pathways of Ca 2 ion fluxes will be analyzed at the level of the plasma membrane, the sarcoplasmic reticulum and the mitochondria. Further attempts will be made to resolve the acetylcholine receptor and to analyze the individual subunits. We shall try to define the lipid requirements of this channel with emphasis on the neutral lipid which we have shown to be required.